Measurement and analysis of pavement marking retroreflectivity

Retroreflective pavement markings enhance road safety by increasing visibility of roadway delineation for road users. In most countries, authorities responsible for road safety do not have performance intervention criteria and standards, and rely on fixed-time interval maintenance programs. This practice is undergoing change via the introduction of mobile retroreflectivity recording units. The focus of this study is to investigate the use of standard mobile retroreflectivity recording units and to analyse the observed retroreflectivity data to evaluate the state of pavement markings under investigation. The centreline pavement marking retrorefl/ectivity data collected by Queensland Department of Main Roads using the ECODYN mobile retroreflectivity recording unit are analysed to determine how the factors such as pavement surface type and traffic environment relate to retroreflectivity performance. It has been found that the mobile retroreflectivity recording unit with in-built processing capabilities can be implemented for identifying the requirements of maintenance programs, as well as to relate the observed retroreflectivity with other factors such as pavement surface type and traffic environment. The observed data indicated that there is a disparity between urban and rural roads of southeast Queensland in terms of centreline pavement marking retroreflectivity qualities. Asphalt surfaces, common in urban environments, were found to have average retroreflectivity over 200 mcd/m2/lux, whereas sprayed seal surfaces, common in rural environments, averaged below 170 mcd/m2/lux. About one-third of the roads used in the analysis fell below the generally accepted minimum threshold of 150 mcd/m2/lux at the time of observation.

An assessment of existing bicycle advisory pavement marking on urban roads

Bicycle advisory treatments are used to advise road users of the potential presence of cyclists and of the location where cyclists may be expected to ride on a road. They include pavement markings, warning signs, guide signs, and as such have no regulatory function. The most common type of bicycle advisory pavement markings is the shared lane marking. Other forms of bicycle advisory pavement marking have also been trialled and used in several local jurisdictions. The bicycle awareness zone is an example of such facility which has been trialled and used in southeast Queensland, Australia since the late 1990s. A bicycle awareness zone is similar to shared lane marking in principle but differs in the type of logo and, in some cases, location of its placement on the road. This study assesses the operational and safety issues at three bicycle awareness zone sites by analysing video-assisted observation data collected in 2011 by Queensland Department of Transport and Main Roads, Australia. Of the several applications of bicycle awareness zones, this study only covers a particular application where the centre of the bicycle symbol is placed exactly over the parking edge line. Unlike previous studies, which mostly covered before-and-after evaluations of bicycle advisory pavement markings, the focus of this study is to assess whether the placement of bicycle awareness zone symbols has been successful. The aggregated results from video-assisted observational data show that the cyclists did not always track themselves over the centre of the symbols. Rather, both the cyclists' lateral tracking positions and road user interactions varied with the widths of kerbside parallel parking space. Since the bicycle awareness zone symbols are not positioned on the cyclists' desired line of ride on some roads, their operational effectiveness and safety value are questioned.

Pavement cafes as the activity zone in the social life of neighbourhood centres

This paper reports the findings from a research project that examines the relationship between urban design and the physical environment, and aspects of social and communal life in suburbs. Australian suburbs are perceived to be lacking in vitality and sociability. To address this, three suburban commercial streets were selected for investigation. Through documents and maps of the residents’ activities and behaviour, this study aims to identify the popular zones of activity and investigate the physical characteristics that encourage a sociable atmosphere in activity zones. The observation of activities in the three streets has been registered in tables relative to the date and time of occurrence. According to the behavioural mappings, the zones of activity are mostly shaped around pavement cafes and popular everyday food stores. Since more than half the activities have been observed to be initiated from the pavement cafes, this paper will investigate how the physical qualities of commercial streets such as the width of the pavements, personalization, soft edges and greenery have contributed to the pavement café culture in the selected neighbourhood centres.

Epidermal growth factor-induced epithelio-mesenchymal transition in human breast carcinoma cells

PMC42-LA cells display an epithelial phenotype: the cells congregate into pavement epithelial sheets in which E-cadherin and beta-catenin are localized at cell-cell borders. They abundantly express cytokeratins, although 5% to 10% of the cells also express the mesenchymal marker vimentin. Stimulation of PMC42-LA cells with epidermal growth factor (EGF) leads to epithelio-mesenchymal transition-like changes including up-regulation of vimentin and down-regulation of E-cadherin. Vimentin expression is seen in virtually all cells, and this increase is abrogated by treatment of cells with an EGF receptor antagonist. The expression of the mesenchyme-associated extracellular matrix molecules fibronectin and chondroitin sulfate proteoglycan also increase in the presence of EGF. PMC42-LA cells adhere rapidly to collagen I, collagen IV, and laminin-1 substrates and markedly more slowly to fibronectin and vitronectin. EGF increases the speed of cell adhesion to most of these extracellular matrix molecules without altering the order of adhesive preference. EGF also caused a time-dependent increase in the motility of PMC42-LA cells, commensurate with the degree of vimentin staining. The increase in motility was at least partly chemokinetic, because it was evident both with and without chemoattractive stimuli. Although E-cadherin staining at cell-cell junctions disappeared in response to EGF, beta-catenin persisted at the cell periphery. Further analysis revealed that N-cadherin was present at the cell-cell junctions of untreated cells and that expression was increased after EGF treatment. N- and E-cadherin are not usually coexpressed in human carcinoma cell lines but can be coexpressed in embryonic tissues, and this may signify an epithelial cell population prone to epithelio-mesenchymal-like responses.

In situ stabilisation of pavements using cementitious binders

An extensive study was made of the physical properties of a range of cementitiously stabilised materials to determine their suitability for use in in situ pavement construction. This process for recycling existing pavements has considerable environmental and cost benefits. Pavement models incorporating these materials were analysed to determine their structural behaviour.

Environmentally friendly sound absorbing noise barrier made from concrete waste - further developments

This paper reports on the second phase of a research project aimed at the development of an environmentally friendly noise barrier for urban freeways, also known as KMAK [1]. The concrete barrier, which has some unique capabilities to mitigate transportation noise, is made from recycled concrete (RC) aggregate and industrial by-products such as fly ash and reclaimed water. The current developmental work expands on a research project that resulted in a two-layer (2L) concrete barrier. Two prototypes of the 2L barrier were produced, followed by extensive acoustic testing and a number of simulations where standard timber and/or concrete barriers were substituted with KMAK barrier [2]. Current research investigates a variety of architectural finishes applied to the original KMAK barrier with the aim of improving its visual appearance and also fine-tuning its acoustic performance. The new three-layer (3L) barrier optimizes sound absorption in a frequency range characteristic similar to that of transportation noise, especially road traffic noise. Three major aspects related to the development of architectural finishes were considered; environmentally responsible materials, surface features, and production methods. The findings of the current investigation demonstrate that there is a positive correlation between surface features, percentage of perforation as well as depth of the architectural layer, and increased potential of the 3L barrier to mitigate transportation noise. On average, the addition of perforated architectural finish contributes to a 20% increase in sound absorption. The preliminary results also show that the sound absorbency of the 3L barrier can be better controlled and tuned to specific noise frequency than the 2L type. The visual appearance has been significantly improved with the addition of the architectural finish, which makes the barrier an attractive, feasible, and viable alternative to road barriers made from standard concrete or timber.

The influence of climate change on Thorthwaite moisture index on the design of light structures

Significant long term changes in the earth’s climate have occurred in the past but recently there has been more severe climate fluctuation than have occurred in the past few centuries. The effect of this climate change on the foundation conditions of roads and low-rise buildings is costing several hundred billion dollars world-wide. A method which tracks this climate change will be of great value for companies and governments. C.W. Thornthwaite (1948) defined the Thornthwaite Moisture Index (TMI) as the first base for his climate classification system and mapping in the United States. There are 3 important factors to predict ground movement: (a) the degree of moisture index change (b) the depth at which this change occurs and (c) the foundation soil type. The water budget model was used by Thornthwaite (1948) to calculate the moisture index. This paper also discusses two typical examples of the use of this model. Originally TMI’s were mainly used to map soil moisture conditions for agriculture but soon became a method to predict environmental and pavement foundation changes.

Raining blood and money

A fictocritical piece based on a fire in New York.
A girl jumps from the ninth floor of the Asch Building. People on the sidewalk are screaming for her not to jump. But she has to jump. As she stands on the ledge, her back against the open window, the fire is burning the clothes off her back. She has her head bent forward so her hair doesn't catch alight as she waves a handkerchief at the crowd. The windows on the floor beneath her start to explode. Tongues of flame lick at her feet. So she jumps. It's a definite jump, as she bends her knees before she leaps over the edge. It's not a graceful jump. Her arms begin to flail as she struggles to stay upright. There are gasps from the crowd, a few screams. Some people turn away. Others are transfixed, watching her as she falls. Suddenly, her dress catches on a hook jutting out of wall below and she is suspended in the air, mid-fall. But the ladders still can't reach her and so it is just a cruel pause in her inevitable death. She hangs there like a ragdoll until her dress burns itself free from her body and she resumes her fall. She lands on the pavement on the west - ward side of New York University building. Thud-dead...

TMI for urban resilience : measuring and mapping long-term climate change effects on soil moisture

The effect of climate change on the shallow expansive foundation conditions of resident dwellings is costing several hundred billion dollars worldwide. The design and costs of constructing or repairing residential footings is greatly influenced by the degree of ground movement, which is driven by the magnitude of change in soil moisture. The impacts of climate change on urban infrastructure are expected to include accelerated degradation of materials and foundations of buildings and facilities, increased ground movement, changes in ground water affecting the chemical structure of foundations, and fatigue of structures from extreme storm events. Previous research found that residential houses that were built less than five years ago have suffered major cracks and other damage caused by slab movement after record rainfall. The Thornthwaite Moisture Index (TMI) categorises climate on the basis of rainfall, temperature, potential evapotranspiration and the water holding capacity of the soil. Originally TMI was mainly used to map soil moisture conditions for agriculture but soon became a method to predict pavement and foundation changes. Few researchers have developed TMI maps for Australia, but generally, their accuracy is low or unknown, and their use is limited. The aims of this paper are: (1) To produce accurate maps of TMI for the state of Victoria for 100 years (1913 to 2012) in 20 year periods using long-term historical climatic data and advanced spatial statistics methods in GIS, and (2) Analyse the spatial and temporal changes of TMI in Victoria. Preliminary results suggest that a better understanding of climate change through long-term TMI mapping can assist urban planning and guide construction regulations towards the development of cities which are more resilient.

Unlawful acts, unkind architecture and unhelpful perceptions: a case study of Market Square Mall, Geelong

On a quiet Sunday afternoon in January 2015, a 12 year old girl was assaulted in Geelong’s Market Square mall. The attack sparked a media furore over what should be done to address the ongoing safety and amenity issues of this intractable public space. The city’s mayor, Cr Darryn Lyons, responded to the situation by declaring the mall a ‘haunt for bogans and scumbags’ and renewed calls for its demolition. Such rhetoric highlights the exclusionary mindset that casts certain types of people as undesirable inhabitants of public spaces. It also bolsters negative public perceptions of the mall. Once formed, such attitudes are difficult to shift, despite an overall improvement in the area’s crime rates over recent years. Poor perceptions are further reinforced by the soulless nature of the mall’s built fabric and weak urban interfaces. Its formal language is one of hostility, not only towards would-be delinquents, but to all people. The space is furnished with cold stainless steel seats, CCTV cameras and limp, pavement water spouts, while its inactive edges consist of loading bays, security grilles and neglected facades. This paper considers how a more inclusive architecture might be utilised to create a kinder, more generous physical environment that reflects the public nature of the space. While not a quick fix, fostering an architecture that encourages a more equitable use of the mall may diminish the sense of fear, anxiety and suspicion that the space currently elicits, tackling the problem at both a structural and social level.